Please give a lot of attention and participation from the members of the Mechanical Engineering department.

▣ 주   제: Flexible Multifunctional Wide-Bandgap Semiconductor Materials and Devices for Extreme-Condition Photonic, Electronic, 

                 Energy Applications and Personal Healthcare Monitoring Applications

▣ 연   사: Jae-Hyun Ryou 교수

▣ 소   속: University of Houston

▣ 일   시: 2024. 6. 17.(Mon) 10:30

▣ 장   소: 제4공학관 D408호

▣ 초   청: 김해진 교수

▣ 초   록

Flexible electronics is an emerging and widely explored area.  Most research groups in the area focus on fabrication processes to provide mechanical flexibility and their use in bendable and stretchable applications.  Also, most semiconductors employed in flexible electronics are non-single-crystalline thin films which compromise the performance of the flexible devices.  Instead of the conventional process and application developments in flexible electronics, my group studies new flexible single-crystalline semiconductor materials and fundamental device physics of flexible devices.  For the new flexible materials, we developed single-crystalline wide-bandgap group-III-nitride (III-N) semiconductor thin films to take advantage of their high critical field strength, piezoelectricity, chemical/thermal stability, biocompatibility, and radiation hardness.  For the extension of device physics, we focus on the interaction between mechanical force and device characteristics, such as changes in electronic band structures, mobilities of free carriers, and quantum efficiencies of energy conversion.  The presentation will cover various topics of flexible photonic, electronic, energy, and sensing devices.  The new functionality of flexible devices, material-related technical issues, and state-of-the-art device technology will be described.  Specifically, research topics to be presented include (1) direct growth of high-quality single-crystalline semiconductor thin films of AlN on low-cost large-area Si substrates, (2) active piezoelectric polarization engineering of flexible III-N heterostructures and their electronic and photonic devices for quantum efficiency improvement and device characteristics tunability, (3) physical sensor operating in extreme environments such as ~1000 °C, and (4) flexible piezoelectric energy harvesters and sensors for self-powered wearable healthcare monitoring systems such as power generators, pulse sensor, eye-movement sensor, cortisol (stress hormone) sensor, glucose sensor, etc.